What is Reactivity in Dogs?

There are a few things to break down when it comes to reactivity, but fundamentally, it’s a heightened emotional response to a trigger.

Triggers can vary depending on the dog, but some of the most common ones UK dog owners encounter include:
🐕 Other dogs
🧑 People (especially strangers)
🚲 Bicycles and skateboards
🚗 Cars, lorries and motorbikes

If you’ve ever found yourself asking “Why is my dog reactive?” you’re not alone. Many dog owners across the UK struggle with this, and it can feel overwhelming, confusing and even isolating. Understanding where the reactivity comes from is the first step to helping your dog feel safer and more confident in everyday situations. 

Why Is My Dog Reactive?

Reactivity in dogs can have a range of causes. In some cases, it may be linked to genetics or learned behaviours. For others, it might stem from trauma, fear or a lack of fulfilment in their day-to-day life.

Here are a few common reasons dogs may become reactive:

Lack of breed-specific fulfilment: Working breeds like collies, spaniels and shepherds are often bred for high-energy tasks. If they’re kept as pets without the right outlets, they can easily become frustrated or overstimulated. This is a common issue among active dogs living in UK cities or suburban areas. 

Fear or anxiety: Dogs that have had negative experiences, such as being attacked by another dog, may react out of fear. They’re trying to protect themselves and create distance.

Excitement displacement or barrier frustration: Some dogs react because they’re excited and can’t reach what they want. This is often seen when a dog barks and lunges while on the lead, at a window or behind a fence. It can look similar to fear, but the motivation is very different.

Understanding what is driving your dog’s behaviour is essential if you want to help them improve. That’s why we always recommend working with a qualified dog behaviourist in the UK who understands local environments, walking routes and common triggers.

Telling the Difference in Reactivity

There are two main types of reactivity:

Fear-based reactivity: Your dog wants the trigger to move away. This is often caused by anxiety or past trauma.

Barrier frustration: Your dog wants to get closer to the trigger but can’t, which leads to a build up of frustration.

To the average owner or passer by, these behaviours can look identical. Barking, lunging or growling often get misinterpreted. That’s why it’s so important not to guess. If you’re unsure, get professional help from a UK-based dog trainer or behaviourist who can safely assess your dog and guide you through the right plan.

In the meantime, start watching your dog closely. Are their ears forward or pinned back? Is their tail wagging softly or held high and stiff? Are they leaning in or backing away? These details give important clues.

Our dogs are always trying to communicate. As owners, especially in busy areas like UK parks or dog-friendly towns, it’s our job to tune in and respond with understanding.

Is a Reactive Dog an Aggressive Dog?

This is one of the biggest myths we need to address.

Reactivity does not mean aggression.

A reactive dog is not a dangerous dog. In fact, most reactive dogs are simply overwhelmed or trying to manage a situation they find difficult. Aggressive dogs behave differently. They’re usually more deliberate and may go straight to biting without the clear warning signs that reactive dogs give.

Reactive dogs will usually bark, lunge or try to create space long before they even think about using their teeth. It’s their way of saying, “I’m not OK with this.”

That being said, reactivity can escalate if it isn’t managed properly. If you’re based in the UK and noticing these signs, now is a great time to seek help from a local dog behaviourist who specialises in nervous or reactive dogs.

How to Help a Reactive Dog

If your dog is showing signs of reactivity, there are some practical steps you can take straight away:

Avoid known triggers when you can. Choosing quieter walks or crossing the road to give your dog more space isn’t giving in. It’s helping them stay under their stress threshold. Use distance wisely. Keeping your dog at a distance where they notice the trigger but don’t react is the sweet spot for learning.

Get professional help. A qualified UK-based behaviourist who uses positive, reward-based methods can build a personalised plan that suits your lifestyle and your dog’s needs.

Focus on confidence-building. Games like ‘find it,’ basic training in low-pressure environments, and gentle scent work are all great ways to build your dog’s trust in you and the world around them.

Support your dog’s comfort with the right gear. At Nervy Mutt, we know how tough it can be navigating the world with a reactive or nervous dog. That’s why we’ve created our GIVE US SPACE range of hoodies and t-shirts, designed specifically for nervous and reactive dog owners. These comfy, easy-to-wear pieces make it clear to others that your dog needs space, without you having to explain. It’s a simple way to help reduce unwanted approaches, set boundaries and feel more confident while out and about...

If you’re searching for help with a reactive dog in the UK, there are lots of great resources out there, including support groups, online training tools and in-person behaviourists who understand what UK dogs and their owners deal with day to day.

Final Thoughts

Living with a reactive dog in the UK can be tough at times, but you’re not alone. So many dog owners across the country are going through the same thing. With patience, guidance and the right support, things can get better for both you and your dog.

Every bark, lunge or growl is your dog trying to say something. It might not be what you want to hear, but it’s an opportunity to understand them more deeply. You don’t have to face this alone, and with the right approach, there is a path forward.

Looking for more support for your reactive or nervous dog? Subscribe to our newsletter or join our free Facebook support group to connect with other owners, access real-life tips and expert guidance on how to build a calmer, more connected relationship with your dog.